Chemical treatments on human hair such as relaxers, straighteners, waves, perms, oxidative and direct dyes, highlights and bleaches are known to result in hair breakage and loss, dryness, roughness and brittleness, and skin and/or scalp irritation. Such chemical treatments employ various reducing and oxidizing agents, alkalizing agents, and coloring agents that help re-shape, artificially color or decolorize hair. Often times, these treatments are used with the application of heat and mechanical combing or brushing, which may contribute to more damage to the hair. Thus, conventional and customary practice by consumers and hair dressers is to have a waiting period of at least 24 hours, preferably, a few days, in between two different chemical hair treatments in order to prevent or reduce irritation to the skin or scalp and the potential damage to hair caused by different chemical treatments within a short period of time, i.e., a few hours. Moreover, a waiting period of at least 24 hours is generally recommended in order to reduce the chance of having a reaction between different chemical treatments, for example, straightening, then bleaching the hair, resulting in an undesirable hair shade.
One of the problems with hair straightening and relaxing methods is that they may prevent the hair from being dyed or bleached correctly in order to achieve the desired shade or lightening effects, especially when the coloration or bleaching step is conducted immediately after the straightening or relaxing steps. Another problem is that when hair straightening or relaxing is immediately followed by a conventional oxidative hair color that employs hydrogen peroxide as the only and/or primary oxidizing agent, the combined use of peroxide with the other ingredients in the hair straighteners and relaxers can result in significant decrease in the quality of the hair fibers, leading to increased roughness and damage to the hair.
It has now been surprisingly discovered that recently chemically straightened or relaxed hair can be lightened in color by combining a bleach composition comprising at least one oxidizing agent selected from the group consisting of persulfates, perborates, percarbonates, their salts and mixtures thereof, and at least one rheology-modifying agent, with a developer composition comprising hydrogen peroxide and a cosmetically acceptable carrier, in order to form a lightening composition, wherein the pH of the lightening composition is from about 2 to about 7, and applying the lightening composition onto the straightened or relaxed hair.
The degree of lightening of the hair may be expressed in terms of “tone” based on the classification of natural shades, one tone separating each shade from that which immediately follows or precedes it. The tone levels are graded from 1 to 10, one unit corresponding to one tone wherein the higher the tone number, the lighter the shade.
It has also now been surprisingly discovered that lightening of the color of hair can be achieved using the methods and compositions of the present invention, and particularly, using a composition having a pH of from 2 to 7. Also, it has been surprisingly discovered that the color of hair that has been recently straightened or relaxed by an alkali-based composition can be lightened using the compositions and method of the present invention. Moreover, it was surprisingly discovered that by using the inventive system, it was possible to achieve acceptable degrees of lightening of the color of the hair that corresponds to an increase in color tone height of up to 4.
The present invention also provides a way to neutralize the hair after it has been treated with a relaxer or straightening composition without having to use a conventional neutralizing composition after such treatment. The method and compositions of the present invention also provide a way to correct the undesirable noticeable greenish yellow to yellowish brown tinge to the hair that results from straightening or relaxing, especially when one has naturally gray hair. At the same time, the use of the present invention reduces the chance of degradation of hair keratin, thus decreasing the chance of hair breakage and loss and allowing the hair to retain a desirable softness and shape.